Smart Material Actuated Fasteners

ABSTRACT

A smart material actuated fastener is provided. In another aspect, a fastener includes a shape memory material and a non-shape memory material with the shape memory material being a minority of the total fastener materials. A further aspect provides a fastener having workpiece-engaging surfaces made of an inactive and non-shape memory material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/029,097, filed on Sep. 17, 2013, which is a continuation ofInternational Patent Application No. PCT/U52012/028009, filed on Mar. 7,2012; which claims benefit of U.S. Provisional Patent Application No.61/562,158, filed on Nov. 21, 2011; and U.S. Provisional PatentApplication No. 61/453,597, filed on Mar. 17, 2011, all of which areincorporated by reference herein.

BACKGROUND AND SUMMARY

The present invention relates generally to fasteners and moreparticularly to a smart material actuated fastener.

Recently, some researchers have theoretically disclosed the use of shapememory polymers for fasteners. For example, reference should be made toU.S. Patent Publication No. 2010/0154181 entitled “Shape MemoryFastener” published on Jun. 24, 2010, and U.S. Patent Publication No.2009/0235494 entitled “Active Material Based Fasteners Including CableTies and Twist Ties” which published on Sep. 24, 2009, both of which areincorporated by reference herein. It is noteworthy, however, that thefasteners of most of the disclosed concepts are entirely made of theshape memory polymeric material. This is extremely disadvantageous froma practical standpoint due to the very high cost of the shape memorypolymers and due to the likely fastening performance degradationthereof.

In accordance with the present invention, a smart material actuatedfastener is provided. In another aspect, a fastener includes a shapememory material and a non-shape memory material with the shape memorymaterial being a minority of the total fastener materials. A furtheraspect provides a fastener having workpiece-engaging surfaces made of aninactive and non-shape memory material. Still another aspect of thepresent fastener includes legs which are moved in response to anenergization change of a shape memory material. In another aspect, atleast a portion of a shape memory material is internally located and/orinsert molded within an inactive material. Still another aspect employsa fastener assembly with a generally rigid segment having a curvedsurface or cavity which secures an elongated tube, wire or othercomponent workpiece thereagainst with the assistance of a shape memorymaterial.

The present invention fastener is advantageous over prior devices suchthat the shape memory material allows for more secure attachment andfastening of the present fastener to the workpiece(s) but withoutgreatly increasing the part expense. Additionally, the present fasteneradvantageously uses conventional polymeric or metallic materials, whichare inactive upon energization, on workpiece-engaging surfaces to obtainthe workpiece insertion and extraction forces required but while alsoproviding an actuation force with a shape memory or active material in aportion of the fastener which is not directly interfacing with theworkpiece and/or in a location which is more tolerant of the performancecharacteristics unique to such shape memory materials. Additionaladvantages and features of the present invention will become apparentfrom the following description and appended claims taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an embodiment of a fastener of thepresent invention inserted in workpieces;

FIG. 2 is a perspective view showing the fastener of FIG. 1;

FIG. 3 is a perspective view showing a shape memory material of thefastener of FIG. 1;

FIG. 4 is a perspective view showing the fastener of FIG. 1 in anactuated and workpiece-engaging condition;

FIG. 5 is a perspective view showing the fastener of FIG. 1 in theactuated condition;

FIG. 6 is a perspective view showing the shape memory material employedin the fastener of FIG. 1 in the actuated condition;

FIG. 7 is a perspective view showing another embodiment fastener of thepresent invention inserted in workpieces;

FIG. 8 is a perspective view showing the fastener of FIG. 7;

FIG. 9 is a perspective view of a shape memory material employed in thefastener of FIG. 7;

FIG. 10 is a perspective view showing the fastener of FIG. 7 in anactuated and workpiece-engaging condition;

FIG. 11 is a perspective view showing the fastener of FIG. 7 in theactuated condition;

FIG. 12 is a perspective view showing the shape memory material employedin the fastener of FIG. 7 in the actuated condition;

FIG. 13a is a diagrammatic side view showing another embodiment fastenerof the present invention inserted in workpieces;

FIG. 13b is a diagrammatic side view of the fastener of FIG. 13a in anactuated and workpiece-engaging condition;

FIG. 14a shows another embodiment fastener of the present inventioninserted in workpieces;

FIG. 14b is a diagrammatic side view showing the fastener of FIG. 14a inan actuated and workpiece-engaging condition;

FIG. 15 is a diagrammatic side view showing another embodiment fastenerof the present invention inserted in workpieces;

FIG. 16 is a diagrammatic side view showing the fastener of FIG. 15 inan actuated and workpiece-engaging condition;

FIG. 17 is a perspective view showing another embodiment fastener of thepresent invention inserted in workpieces;

FIG. 18 is a diagrammatic side view showing the fastener of FIG. 17;

FIG. 19 is a diagrammatic side view showing the fastener of FIG. 17 inan actuated condition;

FIG. 20 is a diagrammatic side view showing another embodiment fastenerof the present invention in an open position;

FIG. 21 is a diagrammatic side view showing the fastener of FIG. 20 inan actuated, closed and workpiece-engaging condition;

FIG. 22 is a diagrammatic side view showing another embodiment fastenerof the present invention in an open condition;

FIG. 23 is a diagrammatic side view showing the fastener of FIG. 22 inan actuated, closed and workpiece-engaging condition;

FIG. 24 is a diagrammatic top view showing a shape memory materialemployed with the fastener of FIG. 22;

FIG. 25 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 26 is a diagrammatic side view of the fastener of FIG. 25 in anactuated condition;

FIG. 27 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 28 is an enlarged and cross-sectional view showing a portion of thefastener of FIG. 27 with a bolt inserted therein;

FIG. 29 is an enlarged and cross-sectional view like that of FIG. 28 inan actuated and bolt-engaging condition;

FIG. 30 is a diagrammatic side view of another embodiment fastener ofthe present invention with a post inserted therein;

FIG. 31 is a diagrammatic side view showing the fastener of FIG. 30 inan actuated and post-engaging condition;

FIG. 32 is a side elevational view showing the fastener of FIG. 30;

FIG. 33 is a top elevational view showing the fastener of FIG. 30;

FIG. 34 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 35 is a diagrammatic end view showing the fastener of FIG. 34;

FIG. 36 is a diagrammatic side view showing the fastener of FIG. 34 witha workpiece inserted therein and a bolt exploded therefrom;

FIG. 37 is a diagrammatic side view showing the fastener of FIG. 34 inan actuated and workpiece-engaging condition;

FIG. 38 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 39 is a diagrammatic side view showing the fastener of FIG. 38 inan actuated and workpiece-engaging condition;

FIG. 40 is a diagrammatic side view showing another embodiment fastenerof the present invention in an actuated and open condition;

FIG. 41 is a diagrammatic side view showing the fastener of FIG. 40 in aclosed and workpiece-engaging condition;

FIG. 42 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 43 is a diagrammatic side view showing the fastener in FIG. 32 inan actuated and workpiece-engaging condition;

FIG. 44 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 45 is a diagrammatic side view showing the fastener of FIG. 44 inan actuated and workpiece-engaging condition;

FIG. 46 is a diagrammatic side view showing another embodiment fastenerof the present invention with workpieces inserted therein;

FIG. 47 is a diagrammatic side view showing the fastener of FIG. 46 inan actuated and workpiece-engaging condition;

FIG. 48 is a diagrammatic side view showing another embodiment fastenerof the present invention with a workpiece inserted therein, in a relaxedstate;

FIG. 49 is a fragmentary perspective view showing an active materialportion of the fastener of FIG. 48, in the relaxed state;

FIG. 50 is a diagrammatic side view showing the fastener of FIG. 48, inan activated state;

FIG. 51 is a fragmentary perspective view showing the fastener of FIG.48, in the activated state;

FIG. 52 is a diagrammatic side view showing another embodiment fastener,in a relaxed state;

FIG. 53 is a perspective view showing an active material portion of thefastener of FIG. 52, in a relaxed state;

FIG. 54 is a diagrammatic side view showing another embodiment fastenerof the present invention;

FIG. 55 is a diagrammatic bottom view showing the fastener of FIG. 54;

FIG. 56 is a cross-sectional view showing another embodiment fastener ofthe present invention, in a relaxed state;

FIG. 57 is a cross-sectional view of the fastener of FIG. 56, in anactivated state;

FIG. 58 is a side elevational view showing another embodiment fastenerof the present invention, in a relaxed state;

FIG. 59 is a side elevational view showing the fastener of FIG. 58, inan activated state;

FIG. 60 is a perspective view of another embodiment fastener of thepresent invention;

FIG. 61 is a cross-sectional view, taken along line 61-61 of FIG. 60,showing the fastener, in a relaxed state;

FIG. 62 is a cross-sectional view like that of FIG. 61, showing thefastener, in an activated state;

FIG. 63 is a perspective view showing another embodiment fastener of thepresent invention;

FIG. 64 is a cross-sectional view, taken along line 64-64 of FIG. 63,showing the fastener, in a relaxed state;

FIG. 65 is a cross-sectional view like that of FIG. 64, showing thefastener, in an activated state;

FIG. 66 is a cross-sectional view showing another embodiment fastener ofthe present invention, in a relaxed state;

FIG. 67 is a perspective view showing another embodiment fastener of thepresent invention, in a relaxed state;

FIG. 68 is a side elevational view showing the fastener of FIG. 67, inrelaxed and activated states;

FIG. 69 is a perspective view showing another embodiment fastener of thepresent invention;

FIG. 70 is a cross-sectional view, taken along line 70-70 of FIG. 69,showing the fastener;

FIG. 71 is a side elevational view showing another embodiment fastenerof the present invention, in a relaxed state;

FIG. 72 is a side elevational view showing another embodiment fastenerof the present invention, in a relaxed state;

FIG. 73 is a side elevational view showing the fastener of FIG. 72, inan activated state;

FIG. 74 is a perspective view showing another embodiment fastener of thepresent invention, in a relaxed state;

FIG. 75 is a top elevational view showing the fastener of FIG. 74, in anactivated state;

FIG. 76 is a perspective view showing another embodiment fastener of thepresent invention, in an activated state;

FIG. 77 is a side elevational view showing the fastener of FIG. 76;

FIG. 78 is a top elevational view showing the fastener of FIG. 76;

FIG. 79 is a side elevational view, taken 90° from that of FIG. 77,showing the fastener, in an activated state;

FIG. 80 is a cross-sectional view, taken along line 80-80 of FIG. 77,showing the fastener, in a relaxed state; and

FIG. 81 is a cross-sectional view like that of FIG. 80, showing thefastener, in an activated state.

DETAILED DESCRIPTION

An embodiment of a smart material actuated fastener 31 is shown in FIGS.1-6. Fastener 31 includes a laterally enlarged head 33 with a generallycircular periphery 35. A stem 37 longitudinally projects from head 33 ina generally perpendicular manner to the laterally enlarged direction.Stem 37 includes at least two flexible legs 39 separated by alongitudinally extending gap 41. Legs 39 are optionally joined at anintermediate waist section 43. Tapered distal ends 45 of legs 39 providea lead-in point to assist insertion of the nominal and free positionfastener (as shown in FIGS. 1 and 2) into a hole within a pair ofworkpieces 47 and 49. Workpieces 47 and 49 are preferably automotivevehicular panels such as stamped sheet metal panels, interior trimpanels, an instrument panel, components or the like. The fastener canattach to one or more of the workpieces depending on the specific use.

A smart or active material member or actuator 51 is insert molded intoan inactive polymeric resin during an injection molding process tocreate fastener 31. In this embodiment, smart material member 51 ispreferably a stamped, shape memory metallic alloy which has a generallyW-shape in its free and unactuated condition, defined by a total lengthat least twice, and more preferably at least four times as long as widthand thickness dimensions. Upstanding outer segments 53 of smart materialmember 51 are entirely internal within the inactive polymer of legs 39and a bridging segment 55 is externally exposed as it extends betweenlegs 39 within gap 41. Turned end segments 57 of smart material member51 are preferably exposed at a top surface of head 33 to assist inlocating the smart material member when it is placed against aninjection mold during insert molding, but ends 57 may alternately beentirely encapsulated within the inactive polymer of head 33.

When in its nominal, free and unactuated condition, smart material 51has a folded over configuration such that legs 39 have their naturallymolded, longitudinally projecting orientation. When an external energysource 59, such as an electrode gun, energizes smart material member 51,bridging segment 55 returns to its initial preformed “memory”orientation, which in this embodiment is straight. Therefore, whenactuated, bridging segment 55 of smart material member 51 outwardlybiases legs 39 and causes workpiece-engaging external surfaces 61thereof to contact against a bottom surface of workpieces 47 and 49while firmly securing a workpiece-engaging bottom surface of head 33against an opposite outer surface of workpieces 47 and 49.

In this embodiment it is noteworthy that smart material member 51 isspaced away from the workpiece-engaging surfaces of the fastener. Thisallows the inactive polymeric material to beneficially meet itsflexibility, tensile strength, color matching, ultraviolet lightresistance, tolerance consistency and other such criticalworkpiece-to-fastener performance characteristics without degradationdue to the different performance characteristics of the shape memorymaterial. Furthermore, the smart material constitutes a minority, andpreferably less than twenty-five percent, of the weight and/or volume ofthe total fastener. This reduces the total material cost of thefastener. Therefore, the specified combination of smart and inactivematerials creates synergistic functional and economic benefits.

The injection molded portion of fastener 31 is preferably made of apolymeric resin which is a non-shape memory material, essentiallyinactive when acted upon by energization source 59. Exemplary inactivepolymeric materials include and are not limited to polypropylene,acrylonitrile butadiene styrene (ABS), nylon, acetel, polyester,thermoplastic elastomer, and variations thereof whether filled orunfilled.

Nonlimiting and exemplary shape memory metallic alloys for smart member51 can be found in the following U.S. Patent Publication Nos.:2007/0044868 entitled “Ti-Based Shape Memory Alloy Article” which waspublished on Mar. 1, 2007; and 2005/0263222 entitled “Cu—Zn—Al(6%) ShapeMemory Alloy with Low Martensitic Temperature and a Process for itsManufacture” which published on Dec. 1, 2005; both of which areincorporated by reference herein. Alternately, the shape memory materialcan be a shape memory polymer such as that disclosed in U.S. Pat. No.7,276,195 entitled “Maleimide Based High Temperature Shaped MemoryPolymers” which issued to Tong on Oct. 2, 2007, which is incorporated byreference herein. The activation energy may take the form of thermalchanges, photons (e.g., from a laser), vibrations, electrical current,microwaves, or the like. This energization is performed in a generallynon-contact manner such that no deformation through contact is createdto actuate the smart member; in other words, no physical bending,pinching or direct mechanical type action due to tools (e.g., hammers,pliers, presses or punches) are acting upon the smart member to actuateit.

FIGS. 7-12 illustrate another embodiment of the smart material actuatedfastener. This exemplary fastener 71 includes a head 73 and a stemdefined by a pair of longitudinally extending legs 75. A generallyU-shaped (in a free state) smart material member or actuator 77 isinsert molded within head and legs 73 and 75, respectively. A pair oftransversely extending notches 79 are positioned at a trough segment 81of smart member 77. Outwardly turned end segments 83, a middle area ofupstanding segments 85 and trough segment 81 are externally visible fromthe final molded fastener while the remainder of smart member 77 isinternally hidden and encapsulated within the inactive majority materialof fastener 71. Again, smart member 77 is preferably a shape memorymetallic alloy while the remainder of fastener is injection molded andinactive polymeric resin.

In the free and molded state, fastener 71 has the straight legconfiguration shown in FIGS. 7 and 8, to allow for easy insertion of thelegs through a hole in workpieces 47 and 49. Upon actuation, however,trough 81 of smart member 77 tries to return to its memory position byupwardly folding while open gaps 87 in legs 75 control and allow foroutward expansion of both the inactive material and smart member segmentthereat, as can be observed in FIGS. 10 and 11. This allowsworkpiece-engaging surfaces 89 on the outer sections of legs 75 tocontact and press against the underside surface of workpiece 49. Thus,smart member 77 takes on a somewhat hourglass or modified W-shape whenin its actuated and “memory” condition. Again, it is noteworthy that thesmart material is a minority of the total fastener weight and/or volume,and also is spaced away from the workpiece-engaging surfaces.

FIGS. 13a and 13b show another embodiment fastener 101 in a free, moldedstate and an actuated fastening state, respectively. Fastener 101includes a laterally enlarged head 103 and a longitudinally extendedstem, including a pair of flexible legs 105. A generallyinverted-V-shaped smart material member 107 is insert molded completelyinternal to legs 105. In this exemplary embodiment, when legs 105 offastener 101 are initially inserted into a hole 109 of workpieces 47 and49, a radial gap is present between an outer periphery 111 and aninternal surface defining a hole 109. In the actuated condition of FIG.13b , however, smart material member 107 is energized by externalactuator 59 and attempts to return to its flat “memory” position.Therefore, smart member 107 laterally expands width of periphery 111 toessentially fill up hole 109 of the workpieces while also outwardlyexpanding and angling legs 105 to compress adjacent portions ofworkpieces 47 and 49 between workpiece-engaging surfaces 113 of legs andan underside workpiece-engaging surface 115 of head 103.

Smart member 107 can alternately move workpiece-engaging surfaces 113 oflegs 105 to a generally co-linear position essentially parallel tounderside surface 115 of head 103. As shown in FIG. 13b , smart material107 greatly increases the extraction forces required to remove the setand actuated fastener 101 from the workpieces. In this embodiment, smartmember 107 is preferably a shape memory metallic alloy but mayalternately be a shape memory polymer.

FIGS. 14a and 14b are similar to the prior embodiment, except that asmart material member 121 is positioned along an in-seam of legs 123.Hence, smart member 121 is externally exposed from a fastener 125,however, it is still spaced away from the workpiece-engaging surfaces.This configuration is advantageous since insert molding is not requiredand smart material member 121 can simply be adhesively bonded, slidwithin molded grooves, or have sonically welded or heat staked posts ofthe inactive polymer legs attached thereto. This also beneficiallyallows direct exposure of an entire surface of the smart material memberto external energy source 59.

Another embodiment fastener 131 is illustrated in FIGS. 15 and 16. Inthis embodiment, fastener 131 has a laterally enlarged head 133 and alongitudinally extending stem 135 perpendicularly projecting therefrom.An annular barb 137, semi-circular detent or other protruding formationis located on stem 135 on the opposite side of workpieces 47 and 49 fromthe head. A smart material member 139 is insert molded or otherwiseplaced into the middle of stem 135 prior to insertion of fastener 131into the workpieces. Upon actuation, smart material member 139 laterallyexpands which also serves to laterally push barb formation 137 outwardlyto provide additional contact against an underside of workpiece 49opposite workpiece engaging surface 141 of head 133. Optionally, slotsmay be provided to allow for the lateral expansion of the inactivepolymeric or even metallic material of stem 135. It also envisioned thata different energization condition be later employed to reverse themovement of smart member 139 and barb formation 137. For example, ifheat (e.g., greater than 125° C.) expands the smart member then anextremely cold condition (e.g., less than −40° C.) may contract thesmart material so that fastener 131 can be more easily removed from theworkpieces.

Still another embodiment fastener 151 can be observed in FIGS. 17-19.This fastener includes a laterally enlarged head 153 and a stem definedby a pair of spaced apart legs 155. Multiple branches 157, each having aflexible and semi-conical shape extend from an outside surface of eachleg, are downwardly pointed toward a distal lead-in end 159 of fastener151. This creates a Christmas tree-like configuration. Head 153, legs155 and branches 157 are all injection molded from an inactive polymericresin. A smart material member 161 has a pair of opposed corners insertmolded into a middle portion of legs 155 with intermediate sectionsbridging within a gap between the legs. Smart material member 161 ispreferably shape memory metallic alloy, such as a preformed wire, whichhas a generally diamond shape in the unactuated and free condition. FIG.19 illustrates the workpiece-engaging condition where external energysource 59 actuates smart member 161 so that it tries to return to itsmemory shape. In this situation, smart member 161 outwardly rotates legs155 relative to head 153 to more firmly engage branches 157 against anunderside of workpiece 49.

Referring to FIGS. 20 and 21, a fastener 171 includes a flexible andelongated body or band 173 with opposite ends thereof. One end has amale attachment formation 175 projecting therefrom while an opposite endhas a female receptacle attachment formation 177 formed thereon. Agenerally C cross-sectionally shaped smart material member 179 islocated within inactive outer housing 180 of receptacle 177 with acentral opening accepting insertion of male attachment formation 175.

Upon energization, smart material 179 within female receptacle 177constricts to firmly press against and attach to male formation 175.This serves to hold closed the ends of band 173 such that an internalworkpiece-engaging surface 181, of generally circular shape, compressesagainst and holds together elongated workpieces 183 such as wires,cables, or hoses, as is shown in FIG. 21. It is noteworthy that all ofbody 173 and male attachment formation 175 are made of an inactive andnon-shape memory material such as a polymeric resin or stamped springsteel. It is alternately envisioned that the smart material can belocated on the male attachment formation to expand within a totallyinactive material receptacle. It is also alternately envisioned that oneor more detents, projections, depressions or knurl patterns canadditionally be provided between smart material member 179 and maleformation 175 to provide greater fastening friction.

FIGS. 22-24 illustrate a further embodiment fastener 191. This fastenerhas a flexible body defined by a pair of body-halves or legs 193 joinedby a middle hinge 195 or handle outwardly projecting therefrom oppositedistal, inwardly turned ends 197. Legs 193 and hinge 195 are completelymolded from an inactive and non-smart material polymeric resin, is madefrom an inactive wire, or stamped from an inactive spring steelmaterial. Curved internal workpiece-engaging surfaces 197 are created onlegs 193 so as to contact against and hold an elongated, generallycylindrical workpiece 199, such as a tube, wire or cable, when ends 197are closed as illustrated in FIG. 23. A smart material actuator member201 has a generally uniform cross-section and somewhat oval top viewshape with a through-bore 203 therein. Smart member 201 externallysurrounds a section of hinge 195 such that when it is actuated, it pullslegs 193 toward each other so as to secure workpiece 199 therein.

Another fastener embodiment is shown in FIGS. 25 and 26. A pair ofopposed snap-fit fasteners 211 each have an enlarged barb-like head 213adjacent to an end of an elongated and flexible stem or shaft 215. Shaft215 perpendicularly projects from a base component 217, such as aclosure, trim panel, or other device. A smart material member 219 spansbetween barbs 213 in a folded or pleated free state when in the nominal,unactuated condition. Ends of smart member 219 are insert molded orotherwise attached internally to barbs 213. When energized as shown inFIG. 26, smart material member 219 constricts and pulls barbs 213 closertogether and/or lessens movement between the snap-fit fasteners. Thesmart material is preferably metallic and the barb/shaft is preferablypolymeric.

In an alternate variation, an L-shaped smart material member 221 isinternally or externally positioned at the bend between base 217 andproximal end of shaft 215. Thus, when smart material member 221 isenergized, it can stiffen or move to encourage, or alternately, deterflexure of the snap-fit relative to the base. Barb 213 and/or theadjacent section of shaft 215 can be configured to engage a workpiece,such as an edge or slot in a flat plate, box, moveable lid or the like.Thus, member 221 changes forces for snap fit-to-workpiece engagement anddisengagement depending upon its energization state and the actuationcharacteristics of the smart member.

Referring now to FIGS. 27-29, an additional embodiment fastener 231 hasa pair of generally parallel legs or side walls 233 and 235 connectedtogether by an end wall 237. An opposite open end 239 is provided toallow for insertion of one or more workpieces between walls 233 and 235.An inwardly turned annular flange 241 in wall 235 defines a holetherethrough which temporarily retains a bolt 247 prior to workpieceengagement. Coaxially aligned therewith, an outwardly turned annular nutor flange 243, made of shape memory metallic material, is internallylocated within inactive polymeric wall 233. When actuated, the smartmaterial of flange 243 will inwardly expand to decrease thecorresponding hole opening thereby firming engaging a threaded shaft 245of bolt 247, or other male member extending therethrough. It isalternately envisioned that reverse energization will cause the smartmaterial to return to its initial wider hole condition thereby allowingmore easy removal of the threaded shaft.

Another embodiment fastener 261 is observed in FIGS. 31-33. Fastener 261is of a push-nut variety including an inactive outer segment 263, havinga generally flat annular shape, with four upturned and inwardlyprojecting teeth 265 extending therefrom. Slots 267 radially projectfrom a central through-bore 269 and separate each adjacent pair of teeth265. The teeth are formed to have a generally triangular configurationwith tapered internal edges. The internal edges 271 are provided with alayer of smart material which can be actuated to move toward a maleshaft 273 extending through the bore 269. When energized (see FIG. 31),the bore diameter is smaller and the tapered edges bite into and engagethe workpiece shaft 273. Shaft can either be a polymeric or softmetallic member. It is preferred that fastener 261 be made from astamped spring steel material with the smart material being a shapememory metallic alloy or polymer attached thereto. It is alternatelyenvisioned that at least a portion or all of each tooth 265 can be madefrom the shape memory material although it is preferred that theinactive material be a majority of the fastener weight.

Referring to FIGS. 34-37, another embodiment fastener 291 includes apair of predominantly parallel legs or side walls 293 and 295, connectedby a deformable end wall 297. An open end 299 is positioned opposite endwall 297 to allow entry of one or more workpieces 301 therein betweenwalls 293 and 295. An internally threaded boss or nut 303 extends fromor is insert molded in inactive polymeric wall 293. An annular collar305 is insert molded in and projects from inactive polymeric wall 295coaxial with nut 303. When actuated, a threaded shaft 307 of a bolt 309engages with nut 303 and projects through a hole 311 inside workpiece301 in a device-like configuration, as shown in FIG. 37.

A smart material member 313 is only located adjacent end wall 297.Preferably, smart material 313 is a pre-stamped, shape memory metallicalloy, a majority of which is insert molded within inactive polymericend wall 297. The end and side walls are injection molded as a singlepiece and end wall 297 may have thinned sections to encourage itsflexure. Nut 303 and collar 305 are preferably stamped metal of aninactive and non-shape memory nature. When actuated, as is shown in FIG.37, smart material member 313 changes shape and moves end walls 293 and295 to sandwich against and compress outer surfaces of workpiece 301therebetween, whereafter bolt 309 is fully inserted. This type offastener can be attached to either thin or thick, single or multipleworkpiece panels, since the smart material member will simply compressthe walls to whatever thickness the workpiece(s) allow. Alternately, thesmart material member can be entirely externally placed on end wall 297.

FIGS. 38 and 39 illustrate still another embodiment fastener 331.Fastener 331 is preferably an all metal stamped U-clip having a pair ofgenerally parallel legs or sidewalls 333 and 335 connected by a smartmemory material end wall 337. An integral and internally threaded bossor nut 339 is provided in wall 333 and an internally offset tongue 341extends from wall 335. Workpieces 47 and 49 extend through an open end343 of fastener 331 and are compressed between workpiece-engagingsurfaces of tongue 341 and wall 333. The side walls and tongue are allmade of inactive and non-smart material. Upon activation, smart materialend wall 337 moves from a generally straight configuration (FIG. 38) toa folded configuration (FIG. 39) thereby moving side walls 333 and 335toward each other. A threaded bolt 345 is thereafter inserted in aclevis-like manner.

FIGS. 40 and 41 show a different embodiment fastener 361. In thisembodiment, fastener 361 includes a generally rigid block 363, made ofan inactive and non-smart material, such as a polymer. Block 363 has acurved internal surface 365 defining a central cavity. Block 363additionally has an opening 367 and a laterally extending groove 369between opening 367 and the cavity. A shape memory metallic alloy 371has an outer surface adjacent one end which is adhered, riveted orotherwise attached within groove 369. Upon energization, the smartmaterial retracts or folds to allow workpiece access through opening 367and into the cavity defined by curved surface 365. When the energizationhas been removed, smart material 371 returns to its flat and straightmemory position spanning across opening 367 to prevent removal of atubular or wire workpiece 373 within the cavity. Additionally, laterallyextending flanges may be provided on the block to allow for it to bescrewed or otherwise mounted to another workpiece or a structural membersuch as a factory wall or pillar.

A further fastener embodiment is shown in FIGS. 42 and 43. Fastener 391includes at least four generally rigid blocks or bodies 393 each havingat least one curved workpiece-engaging surface 395 accessible by anopening 397. Adjacent pairs of the blocks are connected by a smartmemory material member 399 which moves the blocks toward each other whenenergized so as to clamp around elongated and cylindrical tube or wireworkpieces 401. Barbed stems 403 or screws optionally secure blocks 393to a workpiece panel 405 or the like. The blocks are made from aninactive and non-shape memory material such as a polymer while the smartmaterial can be made from a metallic alloy, or alternately, a shapememory polymer. It is alternately envisioned that energization can causethe blocks to move apart instead of or in addition to the preferredenergization of the shape memory material for compression.

Reference should now be made to FIGS. 44 and 45 wherein a fastener 425uses a smart material 421, preferably a shape memory polymer attached toan internally curved surface of each inactive polymeric housing, body orblock 423. A pair of blocks 423 are moveable in a clam shell manner froman open and internally accessible position to a closed position as shownin FIG. 44. A living hinge 427, or alternately a piano hinge, couplestogether the two blocks. A cotter pin and loop, snap fit or otheropenable latch can optionally connect the side of fastener 425 offsethinge 427. After tube or wire workpieces 429 are inserted within eachcavity 431, and the blocks are locked shut, the external energizationsource 59 endothermically, photonically, vibrationally or electricallyactuates the shape memory foam material 421 that radially expands inwardby at least 200% to fill up the space while also centering the workpiece429 relative to curved internal surface 422. This advantageouslyself-centers the tube within the cavity and also self-adjusts fordifferent workpiece diameters within the cavity.

FIGS. 46 and 47 illustrate another embodiment fastener 451 which is arouter for wire, cable or tube workpieces 453. A shape memory polymericfoam 455 is attached to an inside surface 457 of a lid or body 459. Ahinge 461 and opposite latch is provided to close fastener 451 after theworkpieces have been loosely inserted therein. Upon externalendothermic, photonic, vibration or electric energization, foam 455expands by at least 200% to fill up the majority of the internal cavity463 inside fastener 451 thereby pushing against an external surface ofeach workpiece 453 and pushing the workpieces against the oppositeinternal surface 465 of the opposite body or housing 467 of fastener451. This advantageously allows for the securing of randomly layingworkpieces within fastener 451, but without requiring harmfulisocyonide-based reaction injection molded materials. Additionally,mounting flanges may be provided to screw fastener 451 to an adjacentworkpiece or factory wall.

Referring to FIGS. 48-51, a fastener 581 includes a body 583, upstandingside walls 585, and inwardly angled and diagonally projecting legs 587.Legs 587 flexibly move relative to side walls 585 and have an opening589 between ends thereof to allow a workpiece 591, such as an elongatedtube or wire, to be inserted therebetween for receipt within areceptacle 593. Body 583, walls 585 and legs 587 are all injected moldedor extruded from an inactive polymeric material. Furthermore, aninternal cradle 595 is made from an active, shape memory material.Cradle 595 includes a central semi-cylindrical segment 597 and distalends 599. Cradle 595 defines a portion of receptacle 593 between body583 and side walls 585. In a relaxed and unenergerized state, as shownin FIG. 49, cradle 595 may optionally include elongated slots 601. Whenactivated by an energy source 59, ends 599′ of cradle 595 upwardlyexpand into the otherwise open space 603 between each leg 587 andadjacent wall 585. Ends 599′ may also be expanded between optionalinternal ribs 605 attached to legs 587 and walls 585. This expansion ofthe activated cradle 595 serves to deter flexure of each leg 587 towardadjacent wall 585 thereby locking legs 587 into their workpiece securingpositions. Body 583 of fastener 581 is secured to a different workpiecepanel or member via screws, rivets, straps or other such supplementalattachments.

FIGS. 52 and 53 show a variation of the immediately preceding fastener.In this embodiment, a similar fastener 621 includes a body 623, sidewalls 625 and flexible legs 627, all of which are made from an activepolymeric material. This embodiment does not include ribs. A cradle 629is of a simpler design such as a semi-cylindrical shape, but without aslot. Cradle 629 is an energizable and active, smart material polymerwhich is expandable within a space 631 between each leg 627 and adjacentwall 625 in order to lock a workpiece 633 therein. This constructionadvantageously allows cradle 633 to swell and enlarge in size toaccommodate different diameter workpieces within the fastener and toallow for axial sliding of workpiece 633 within fastener 621 prior toactivation. Cradle 633 may be mechanically or adhesively bonded to body623.

Reference should be made to FIGS. 54 and 55 for another embodimentfastener. This fastener 651 employs an active polymeric body 653, sidewalls 655 and inwardly angled and flexible legs 657. An elongatedworkpiece tube or wire 659 is inserted in a snap fit manner betweendistal ends of legs 657 and a receptacle 661 in body 653. A central stem663 extends from body 653 and has a laterally enlarged head 665 on anend thereof. Stem 663 and optionally head 665, are injected molded froma smart memory polymer. An installer initially inserts head 665 into agenerally elongated and oval aperture 667 within an inner sheet metalworkpiece 669, which is spaced away from an outer sheet metal workpiece671, which makes this a blind attachment. The installer then rotates thefastener 651 approximately 90° such that enlarged and generally ovalhead is turned to position 665′ offset from the elongation direction ofaperture 667. An energy source then activates the shape memory materialof stem 663 and optionally head 665 so that they enlarge and securelycompress against the back side of inner panel 669. This fastenerconstruction provides a quarter turn fastener as a single piececomponent which can be applied to workpiece panels of varying thickness.In one alternate arrangement, activation of the shape memory materialmay automatically cause the 90° rotation of head 665 such that it doesnot need to be manually performed. In another alternate variation, anoptional finger 681 can laterally extend from body 653 to engage with amating hole in panel 669, thereby deterring reverse rotation of fastener651 after it is in the fully attached position.

FIGS. 56 and 57 illustrate yet another embodiment fastener 701 which canbe used to maintain an automotive vehicle, interior trim panel workpiece(not shown) to a sheet metal workpiece panel 703 or the like. Fastener701 includes a laterally enlarged and generally circular head 705, afrusto-conical umbrella 707 and a hollow stem 709 longitudinallyprojecting perpendicular to head 705. A separate plunger 711 has aproximal end movable within the hollow cavity of 709 and furtherincludes a bulbous head 713 at an opposite distal end thereof. Head 705,umbrella 707, stem 709 and plumber 711 are all injection molded from aninactive polymeric material. A smart member 715 is injection molded ontooutside surfaces of stem 709 and plunger 711 as a pre-assembledcomponent. In its relaxed state, smart member 715 has a substantiallycylindrical outside surface 717 with a laterally extending ring 719annularly projecting from a middle thereof generally parallel to head705. When inserted into the aperture 721 of workpiece panel 703, ring719 can be flexed therethrough when the plunger 711 and smart member 715are fully extended and relaxed. But when activated by an energy source59, as shown in FIG. 57, smart member 715 longitudinally contracts whilelaterally expanding on the back side of workpiece panel 703. Smartmember 715 also seals aperture 721 while causing plunger 711 to retractinto the hollow receptacle of stem 709. In turn, bulbous end 713 andplunger 711 laterally and outwardly push distal ends of stem 709 therebyprovided an additional mechanical force to retain fastener 701 toworkpiece panel 703. It is alternately envisioned that plunger 711 canbe made of an active shape memory material while member 715 can be aninactive PVC or other flexible covering material.

As can be observed in FIGS. 58 and 59, another embodiment fastener 751secures an elongated and generally cylindrical workpiece 753, such as atube or wire, to a sheet metal workpiece panel 755. Fastener 751includes a predominantly cylindrical head 757 which serves to clampelongated workpiece 753 therein. The fastener further includes anintermediate post 759, generally frusto-conical umbrella 761,longitudinally elongated stem 763, and at least a pair of flexible legs765. Umbrella 761 and stem 763 are made from an active, shape memorypolymer while the remainder of fastener 751 is integrally formed byinjection molding from an inactive polymeric material. Thus, afterfastener is inserted within an aperture of workpiece panel 755, externalenergy source 59 energizes the smart material thereby causing expansionof umbrella 761 and/or contraction of stem 763. This allows fastener 751to tightly sandwich workpiece panel 755 between umbrella and ends oflegs 765, thereby accommodating different thickness and/or quantities ofworkpiece panel 755 without requiring a multitude of differently sizedfasteners. This saves part handling and installation inaccuracies withinan assembly plant, while also reducing the cost and complexity ofmanufacturing many differently sized but otherwise similarly appearingfasteners.

Turning now to FIGS. 60-62, grommet fastener 781 employs a hollow,annular body 783 with a generally flat bridging bottom wall 785. A pairof flexible and opposed frusto-conical legs 787 diagonally and outwardlyextend from body 783. A central annular groove 789 is defined betweendistal edges of legs 787 to receive a sheet metal workpiece panel 791therein. An annular smart member 793, made from a shape memory alloymetal or polymer, is pressfit or adhered inside body 783. When energizedby source 59, smart member 793 laterally expands as shown in FIG. 62,thereby pushing body 783 against an aperture of workpiece panel 791defining an aperture 795 therein. Body 783 and wings 787 are preferablymade from a non-active material, such as an elastomeric polymer orrubber, thereby providing a water-tight an air-tight seal for aperture795.

A different embodiment fastener 801 is illustrated in FIGS. 63-65. Thisfastener 801 has a somewhat box-like and cubicle shape defined by sidewalls 803, top wall 805 and bottom walls 807. A flexible leg 809 isupstanding from bottom wall 807 between side walls 803 at each sidethereof. Furthermore, a shape memory alloy actuator 811 is connected toa post 813 extending from top wall 805 and oppositely mechanically oradhesively bonded to bottom wall 807 such that it projects in alongitudinal manner between legs 809. When energized by an externalsource 59, shape memory actuator 811 longitudinally retracts andlaterally expands thereby causing the bottom of fastener 801 to movetoward the top wall (an optional weakened area or gap 815 may beprovided in the side walls to allow for such movement) while the lateralexpansion outwardly pushes legs 809 past a nominal outside of fastener801. This serves to trap one or more workpieces 817 between anoverhanging head 819 extending from top wall 805, and distal ends offlexible legs 809.

A variation of the preceding fastener 801 is shown in FIG. 66. Thisexemplary fastener 851 includes a top wall 853 and overhanging head 855,as well as bottom walls 857 and flexible legs 859. However, a generallyhourglass-shaped smart actuator 861 consists of a shape memory alloy,metallic spring-like member, which is pinned to top wall 853 andmechanically (e.g., insert molded) or adhesively attached to bottom wall857. When activated, the hourglass shape will turn into a longitudinallycompressed and laterally expanded diamond shape thereby outwardlyflexing legs 859 into engagement with a back side of a workpiece 863.

Referring to FIGS. 67 and 68, another embodiment fastener 881 is used tosecure an elongated workpiece such as a tube or wire bundle 883 to asheet metal workpiece panel 885. Fastener 881 includes a laterallyelongated central body 887 and multiple spaced apart and offset legs 889and 891 arcuately extending from lateral edges of body 887. Fastener 881additionally includes a longitudinally elongated stem 893 with multiplefrusto-conical, Christmas tree-like barbs or branches 895 outwardlyprojecting therefrom for engagement with a back side of workpiece panel885. Stem 893 and branches 895 are injection molded from an inactivepolymer while legs 891 are molded from a shape memory polymer ormetallic alloy as one piece with stem 893 and branches 895. In itsrelaxed state, as shown in FIG. 67, legs 889 and 891 are arcuatelycurved but spaced apart in an open condition allowing access byworkpiece 883. But when activated by an external energy source, wings889 and 891 curl toward each other in an interlocking manner as shown inpositions 889′ and 891′ in FIG. 68, thereby collectively encirclingworkpiece 883 therein. It is alternately envisioned that the encircledretention position can be in a relaxed state while the activatedposition can be the open state. As another alternate variation, wings889 and 891, and body 887 can be integrally made from an inactivematerial along with stem 893 and branches 895, however, wings 889 can beinternally and/or externally coated with a shape memory alloy polymer tocause the energized movement of the wings, although certain functionaladvantages may not be fully achieved with this coating approach.

Reference should now be made to FIGS. 69 and 70. This embodimentfastener 901 provides a nut-like head 903 from which laterally extendsshape memory polymer or alloy legs 905 in a somewhat curved and axialmanner. A rim 907 and attached base 909 are attached to distal ends oflegs 905. More specifically, nut-like head 903 is longitudinallyelongated above the generally flat base 909 and has a hollow innercavity 911. The surface defining inner cavity 911 can have internalthreads, barbs or other projecting surface formations to engage with amating weld stud 913, having external threads or other enmeshingpatterns. Weld stud 913 is welded onto a sheet metal workpiece panel915, such as an automotive vehicle component, computer housing,electrical component, or the like. Thus, nut-like head 903 is press-fitor rotatably screwed onto weld stud 913. Moreover, nut-like head 903 andbase 909 are preferably made from an inactive metal or polymericmaterial such that when legs 905 are energized, they act to center base909 relative to nut-like head 903, weld stud 913, and workpiece panel915. Legs 905 also act like floating springs. Base 909 serves as afunctional component, such as an attachment bracket, or may be attachedto a functional component. Alternately, weld stud 913 can be replaced bya bolt, axle or other projecting shaft.

FIG. 71 shows a fastener 931 which serves to attach together two spacedapart workpiece panels 933 and 935. Fastener 931 includes a central body937 made of a smart memory polymer. Furthermore, fastener 931 includes apair of spaced apart umbrellas 939, longitudinally elongated shafts 941coaxially aligned with body 937, and arrowhead-shaped flexible legs 943extending from a distal end of each shaft 941. Legs 943, shaft 941and/or umbrella 939 can be made from a shape memory polymer or alloy, orfrom an inactive polymer. Thus, when energized, the smart materialcontracts thereby snugly sandwiching each workpiece panel between theadjacent umbrella and legs while also causing contraction of body 937 soas to firmly secure together workpieces 933 and 935.

FIGS. 72 and 73 show yet another embodiment fastener 961. This fasteneracts like a blind rivet when energized. Fastener 961 includes aninactive rivet head 963 and inactive rivet body 965 which both havegenerally cylindrical exterior surfaces. Body 965 further includes ahollow internal receptacle 967 and external expansion slot 969 such thatbody can be split apart into legs 971 as shown in FIG. 73. A mandrel 973has an elongated cylindrical shaft 975 and a tapered shoulder 977adjacent a pointed head 979 thereof. When energized from source 59,mandrel 973 retracts within receptacle 967 of rivet body 965, whichcauses shoulder 977 of mandrel 973 to outwardly push legs 971 of rivetbody 965 into back side engagement with one or more workpiece panels981. Such a smart material actuated blind rivet can be used to securetogether components in an automotive vehicle, aircraft, or electronichousing, especially as a temporary tacking rivet if the smart materialmovement is reversible through another energization change.

Referring now to FIGS. 74 and 75, a fastener 1001 is used to securetogether one or more elongated workpieces, such as hollow tubes or wires1003, to a building or vehicular panel. Fastener 1001 includes a base1005, a pair of outer side walls 1007, a pair of diagonally and inwardlyangled snap legs 1009, and a pair of workpiece receptacles 1011 ofgenerally semi-cylindrical shape. A central pivot 1013 upstands from acenter of base 1005 upon which is mounted a generally S-shaped head1015. Head 1015 has laterally extending bridges 1017 terminating intapered hooks 1019. When rotated from an open condition shown in FIG.74, to a locked condition of FIG. 75, hooks 1019 engage within anassociated open space 1021 between associated snap leg 1009 and outerwall 1007, such that bridge 1017 spans across each elongated workpiece1003. Head 1015 and/or pivot 1013 are made from a shape memory alloy orshape memory polymer such that when they are energized, theyautomatically rotate between open and closed positions, or vice versa.The remainder of fastener 1001 is made from an inactive polymericmaterial and can be screwed or otherwise attached to the associatedworkpiece panel adjacent base 1005.

Yet another fastener construction can be observed with reference toFIGS. 76-81. This exemplary fastener 1031 is used to fasten an interiortrim panel, circuit board or other workpiece panel 1033 to a vehicularbody panel, computer housing or other such structural workpiece panel1035. Fastener 1031 includes a head 1037, a post 1039, a circularshoulder 1041, a generally frusto-conical umbrella 1043, alongitudinally elongated and generally cylindrical stem 1045, andfastening legs 1047. Head has a plurality of arms 1055 outwardlyextending therefrom in a somewhat arcuate manner while having diagonallyangled upper edge surfaces 1057. In their relaxed state as shown inFIGS. 76-80, these arms 1055 are contracted toward a longitudinal centerline 1059 of fastener 1031 such that they can easily be inserted througha hole 1061 of workpiece 1033 which then sits on shoulder 1041. A keyway1063 defines a segment of shoulder and is integrally formed as part ofpost 1039 and head 1037, which are all injection molded from a shapememory polymer. When energized, as shown in FIG. 81, arms 1057 radiallyextend outward to the position 1055′ thereby overlapping and sandwichingworkpiece panel 1033 between arms 1057 and shoulder 1041.

Legs 1047 preferably have a somewhat diamond shape terminating in apointed upper end facing toward head 1037 and an undercut conical end1071 opposite head 1037. Laterally pointed knees 1073 of each leg 1047projects through longitudinally elongated slots 1075 in an outside ofstem 1045. Legs 1047 and conical end 1071 are integrally injected moldedfrom a shape memory polymer such that in their relaxed state, as shownin FIG. 80, they are laterally retracted and/or more pliable to allowfor stem insertion through an aperture 1081 and workpiece panel 1035.Thereafter, when energized like FIG. 81, knees 1073 of legs 1047outwardly move and/or become more rigid thereby compressing against aback side of workpiece panel 1035. Moreover, umbrella 1043 is preferablymade from a smart memory polymer such that upon energization, it expandsto further compress against a front side of workpiece panel 1035.Umbrella 1043 is press fit onto stem 1045 adjacent to a bottom surfaceof shoulder 1041. Shoulder 1041 and stem 1045 are preferably injectionmolded as a unitary single piece from an inactive polymeric material.

It is further envisioned that a shape memory material, such as thatemployed for any of the proceeding embodiments, can be used to securealternately constructed fasteners to one or more workpieces. Suchexemplary alternate fasteners are disclosed in U.S. Patent PublicationNos.: 2010/0098515 entitled “Attachment Fastener” which published onApr. 22, 2010; 2009/0191025 entitled “Fastener” which published on Jul.30, 2009; 2009/0066531 entitled “Device for Assembling Two StructuralElements” which published on Mar. 12, 2009; and 2008/0095592 entitled“Clamp for Joining an Add-On Piece to a Base” which published on Apr.24, 2008. All of these patent publications are incorporated by referenceherein.

While various embodiments have been disclosed herein, it should beappreciated that other modifications can be made. For example, multipleheads connected by intermediate necks can be provided on any of thefasteners. While an automotive vehicle and/or factory uses have beendisclosed, it should be appreciated that any of these fasteners can beemployed in automotive vehicles, factories, residential buildings,electronic housings, aircraft or other applications, although all of thepresent advantages may not be realized. Furthermore, additional oralternately shaped legs, stems, bodies and segments can be provided,although various advantages may not be achieved. It should also beappreciated that any feature from any of the disclosed fasteners can beemployed with any of the other disclosed fasteners in an interchangeablemanner, although certain benefits may not be realized. It is intended bythe following claims to cover these and any other departures from thedisclosed embodiments which fall within the true spirit of thisinvention.

1. A fastener comprising: a shape memory material; a non-shape memorymaterial, the shape memory material being a minority of the totalfastener materials; a laterally enlarged head; an elongated stemlongitudinally extending from the head, the head and the stem being madeof the non-shape memory material; a plunger coupled to the stem; aflexible outer member coupled to the plunger and surrounding a leadingend of the stem opposite the head; one of the plunger and the outermember being made of the shape memory material; and the shape memorymaterial longitudinally moving the plunger and the outer member towardthe head and laterally expanding the outer member, when an activationstate changes.
 2. The fastener of claim 1, wherein the stem is hollowand the non-shape memory material is located on at least an externalsurface thereof.
 3. The fastener of claim 2, wherein the shape memorymaterial is the plunger and is at least partially located internallywithin the stem.
 4. The fastener of claim 1, wherein the shape memorymaterial is entirely internal within the non-shape memory material, andthe shape memory material causes a width dimensional change of thenon-shape memory material when the actuation state changes.
 5. Thefastener of claim 1, wherein the shape memory material is polymeric andthe non-shape memory material is polymeric.
 6. The fastener of claim 1,wherein the non-shape memory material creates a hole-sealing grommet,and the shape memory material is internally located within the grommet.7. The fastener of claim 1, wherein the shape memory material moves theplunger within a hollow section of the stem made of the non-shape memorymaterial which is polymeric.
 8. The fastener of claim 1, furthercomprising an umbrella extending from the stem, the shape memorymaterial contacting the umbrella in a fastening condition.
 9. Thefastener of claim 1, wherein the outer member is made of the shapememory material and includes an internal cup-shape adjacent a distal endof the plunger.
 10. A fastener comprising: a laterally enlarged head,the head including non-shape memory material; an elongated stemlongitudinally extending from the head; a plunger coupled to the stem,the plunger including a longitudinally elongated portion and a laterallyenlarged portion in at least one condition; an outer member coupled tothe plunger and the stem; one of the plunger and the outer memberincluding shape memory material; and the shape memory materiallongitudinally moving the outer member toward the head and laterallyexpanding the outer member, when an activation state changes.
 11. Thefastener of claim 10, wherein the shape memory material is the plungerand is at least partially located internally within the stem.
 12. Thefastener of claim 10, wherein the shape memory material is entirelyinternal within the non-shape memory material, and the shape memorymaterial causes a width dimensional change of the non-shape memorymaterial when the actuation state changes.
 13. The fastener of claim 10,wherein the outer member includes a laterally enlarged ring extendingfrom a cylindrical outside surface, the ring being laterally enlargeablewhen the shape memory material is activated.
 14. The fastener of claim10, wherein the outer member is made of the shape memory material andincludes an internal cup-shape adjacent the laterally enlarged portionof the plunger.
 15. The fastener of claim 10, further comprising anautomotive vehicle, interior trim panel secured to the head, and theouter member securing the stem to a sheet metal panel.
 16. A fastenercomprising: a laterally enlarged head, the head including non-shapememory material; an elongated stem longitudinally extending from thehead; a plunger coupled to the stem; an outer member coupled to theplunger; one of the plunger and the outer member including shape memorymaterial; the shape memory material moving a portion of the outer memberwhen an activation state changes; a frustoconical umbrella, the shapememory material moving toward the umbrella if changed from anunfastening condition to a fastening condition; and the outer memberacting as a workpiece hole-sealing grommet when in a fastened condition.17. The fastener of claim 16, wherein the shape memory material is theplunger and is at least partially located internally within the stem.18. The fastener of claim 16, wherein the shape memory material isentirely internal within the non-shape memory material, and the shapememory material causes a width dimensional change of the non-shapememory material when an actuation state changes.
 19. The fastener ofclaim 16, wherein the outer member is made of the shape memory materialand includes an internal cup-shape adjacent a laterally enlarged distalend of the plunger.
 20. The fastener of claim 16, further comprising anautomotive vehicle, interior trim panel secured to the head, and theouter member securing the stem to a sheet metal panel.